Materials World Network: Interfacial Phenomena in Superconducting Heterostructures

材料世界网络：超导异质结构中的界面现象

• 批准号: 0709584
• 负责人: Allen Goldman
• 金额: $ 46.8万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0709584&HistoricalAwards=false
• 关键词: Materials; World; Network; Interfacial; Phenomena

The objectives of this research are to synthesize, characterize, and study experimentally and theoretically properties associated with interfacial phenomena in epitaxial heterostructures consisting of complex oxide superconductors (cuprates), and ferromagnets (manganites) and oxide superconductors incorporated into field effectstructures with oxide gate insulators. This effort combines the techniques developed by the Spanish investigator (Jacobo Santamaria, Universidad Complutense, Madrid) for the fabrication of epitaxial films of oxides using relatively simple high-pressure oxygen sputtering techniques, with the theoretical and experimental capabilities of the US investigators at Minnesota (Allen Goldman) and Georgia Tech (Carlos Sa de Melo) and their collaborators at Argonne (Suzanne ter Velthuis) and Oak Ridge National Laboratories (Maria Varela). The unifying concepts of this effort are the use of spin from an oxide ferromagnet and induced charge from a field effect gate to study the ground state and excited states of high temperature superconducting films.There are two main research themes: (1) Spin injection and related phenomena in complex oxide superconducting/ferromagnetic heterostructures and (2) charge effects and quantum order in complex oxide superconducting nano- films. The effects of spin injection on the quasiparticles and the condensate of cuprate films and the roles of Andreev reflections and the magnetic proximity effect on the spin relaxation time and length in cuprate films are examined. The possibilities of inducing exotic pairing states in ferromagnetic oxides and using the field effect to tune the properties of an "under doped" cuprate in the pseudogap phase into the superconducting state are also explored. A goal of the latter effort is to investigate the use of field effect doping to determine whether the zero-temperature end point of the boundary between the pseudogap and the superconducting phases is a quantum critical point connecting two different superconducting ground states. The experimental tools used to address these issues include electron tunneling and electrical transport, and with collaborators at Oak Ridge and Argonne National Laboratories, electron microscopy and neutron scattering. The theoretical tools used involve many body techniques that parallel and complement the experimental investigations. This international effort allows for strong interaction of students and postdoctoral associates from the US and Spain, which broadens the experience of young scientists in the global scientific community.This award is co-funded with the Office of International Science and Engineering.

这项研究的目的是合成，表征和研究与界面现象相关的与界面现象相关的外观异质结构中的特性，包括复杂的氧化物超导体（Cuprates）和铁磁铁（锰矿）（锰矿）和氧化物超管剂与氧化物彩门登机剂的现场效果结合在一起。 这项工作结合了西班牙研究者（Jacobo Santamaria，Madrid大学的Jacobo Santamaria）开发的技术，用于制造氧化物的外在薄膜，使用相对简单的高压氧气溅射技术，以及Minnesota（Allennes andnesota）（Allennes anden Goldman）的理论和实验能力，以及他们的理论和实验能力Argonne（Suzanne ter Velthuis）和Oak Ridge国家实验室（Maria Varela）。这项工作的统一概念是使用来自氧化物铁磁磁铁的自旋和来自场效应门的诱导电荷来研究高温超导膜的基态和激发状态。这是两个主要的研究主题：（1）复杂的氧化物超导/效力激素杂物的复杂氧化物和相关现象的效果和量子序列（2）复杂的效果，并效应效果，并效应效果。旋转注射对准颗粒的影响以及铜膜的冷凝物以及Andreev反射的作用以及磁接近对铜膜中自旋松弛时间和长度的磁接近效应。还探索了在假磁氧化物中诱导异国情调的配对状态，并利用田间效应调整伪库相中的“掺杂”铜矿的特性到超导状态。后者努力的一个目的是研究使用场效应掺杂来确定伪gap和超导阶段之间边界的零温度端点是连接两个不同的超导基态的量子临界点。 用于解决这些问题的实验工具包括电子隧道和电气传输，以及与Oak Ridge和Argonne National Laboratories，电子显微镜和中子散射的合作者。 所使用的理论工具涉及许多人体技术，它们平行并补充了实验研究。这项国际努力使来自美国和西班牙的学生和博士后同伙进行了牢固的互动，从而扩大了年轻科学家在全球科学界的经验。该奖项与国际科学与工程办公室共同资助。